beta-glucan hydrolases from Aspergillus niger. Isolation of a beta-(1-4)-glucan hydrolase and some properties of the beta-(1-3)-glucan-hydrolase components.

1. The components of an enzyme preparation from Aspergillus niger, which hydrolysed substrates containing beta-(1-->3)- and beta-(1-->4)-glucosidic linkages, were separated by calcium phosphate and Dowex 1 column chromatography. 2. The hydrolytic activity of each fraction from both types of column towards laminaribiose, laminarin, carboxymethylpachyman, pachydextrins, salicin, cellobiose, cellopentaose and swollen cellulose was tested. 3. The activity towards the beta-(1-->3)-glucosidic substrates was found in three well-separated groups of fractions. The differences in action pattern of these groups is discussed. 4. Preparative-scale chromatography that enabled the separation of a beta-(1-->4)-glucan-glucanohydrolase component substantially free of activity towards beta-(1-->3)-glucosidic substrates is described. Residual beta-(1-->3)-glucan-hydrolase activity was removed by adsorption on to insoluble laminarin at pH3.5.